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(单词翻译:双击或拖选)
Ya?l: I was walking my cocker spaniel this morning, and we ran into two other dogs---a great dane almost as tall as I am, and a tiny Chihuahua! I can't believe they are all the same species!
Don: You know, scientists are making great strides in understanding the genes1 that allow such a wide range of shapes, sizes and personalities2 in different dog breeds. Did you know domestic dogs were bred from wolves about 15,000 years ago?
Y: That's pretty recent in evolutionary3 terms, isn't it?
D: Very! Humans have sped up the diversification4 of dogs by selecting for particular physical or behavioral traits such as size, coat type, trainability, and hunting or herding5 ability.
But dogs still show greater variety than any other domesticated6 animal, and for a long time this variance7 has largely been unexplained.
A group of genetics researchers collaborated8 with dog breeders and veterinarians to study the DNA9 from 148 different dog breeds. With such a large sample of genes from very different kinds of dogs, they were able to identify regions in the dog DNA that are important in regulating some key traits that differ between breeds.
Four regions were found that may regulate life span, a breed characteristic that usually decreases with increasing body size. Regions associated with some behavioral stereotypes10 like herding, pointing and boldness were also identified.
Y: What can they do with this information?
点击收听单词发音
1 genes | |
n.基因( gene的名词复数 ) | |
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2 personalities | |
n. 诽谤,(对某人容貌、性格等所进行的)人身攻击; 人身攻击;人格, 个性, 名人( personality的名词复数 ) | |
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3 evolutionary | |
adj.进化的;演化的,演变的;[生]进化论的 | |
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4 diversification | |
n.变化,多样化;多种经营 | |
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5 herding | |
中畜群 | |
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6 domesticated | |
adj.喜欢家庭生活的;(指动物)被驯养了的v.驯化( domesticate的过去式和过去分词 ) | |
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7 variance | |
n.矛盾,不同 | |
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8 collaborated | |
合作( collaborate的过去式和过去分词 ); 勾结叛国 | |
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9 DNA | |
(缩)deoxyribonucleic acid 脱氧核糖核酸 | |
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10 stereotypes | |
n.老套,模式化的见解,有老一套固定想法的人( stereotype的名词复数 )v.把…模式化,使成陈规( stereotype的第三人称单数 ) | |
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11 vets | |
abbr.veterans (复数)老手,退伍军人;veterinaries (复数)兽医n.兽医( vet的名词复数 );老兵;退伍军人;兽医诊所v.审查(某人过去的记录、资格等)( vet的第三人称单数 );调查;检查;诊疗 | |
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